Automobiles and light trucks of current manufacture contain many components that are acquired in packaged form from outside suppliers. The packaged components reduce the time required to assemble automotive vehicles and further improve the quality of the vehicles by eliminating critical adjustments from the assembly line. So-called “wheel ends” represent one type of packaged component that has facilitated the assembly of automotive vehicles. A wheel end couples a road wheel to the suspension system of the vehicle and transfers both radial and axial loads between the wheel and suspension system, all while allowing the wheel to rotate.
The typical wheel end has a housing that is bolted against a steering knuckle or other suspension upright, a hub provided with a drive flange to which the road wheel is attached and also a spindle that projects from the flange into the housing, and an antifriction bearing located between the housing and the hub spindle to enable the hub to rotate in the housing with minimal friction. If the road wheel propels the vehicle, the hub of the wheel end is coupled to a driven axle shaft through a constant velocity (CV) joint to provide a corner module. The CV joint has a stub shaft that projects into the hub spindle, with which it is engaged through mating splines, one in the hub and the other on the stub shaft.
The wheel ends of most automotive vehicles occupy considerable space within the wheels that are mounted on them. After all, the housing of the typical wheel end must possess considerable diameter—first, to accommodate the rows of rolling elements and the raceways along which they roll and secondly to accommodate a CV joint with a stub shaft large enough in diameter to transfer the torque required to propel the vehicle. This leaves less space for brake components.
The escalating cost of fuel for automotive vehicles has led the manufacturers of such vehicles to undertake measures to improve the efficiency of their vehicles—the so-called miles per gallon that the vehicles achieve. To this end, the manufacturers have sought to reduce the weights of their vehicles. Smaller wheel ends would weigh less and further produce less drag torque, and would thus satisfy an objective of the manufacturers.